BI 689648 is primarily investigated for its potential therapeutic applications in treating pulmonary arterial hypertension (PAH). It functions as a soluble guanylate cyclase (sGC) stimulator, which helps to relax blood vessels and improve blood flow in the lungs. This mechanism is crucial for reducing pulmonary vascular resistance and alleviating symptoms associated with PAH, such as shortness of breath and fatigue. Clinical studies are ongoing to evaluate its efficacy and safety in improving exercise capacity and quality of life for patients with this condition. Additionally, its role in targeting sGC makes it a promising candidate for addressing other cardiovascular diseases where vasodilation and improved blood circulation are beneficial.